This application relates to an apparatus for forming a sealed end of a hollow thermoplastic tube. These tubes are used as covers for probes of electronic thermometers and may also be used as containers for elongated objects.
Prior art processes for forming such tubes included multiple steps which entailed the movement of the hollow tube from one work station to another work station in order to complete the formation of the closed end of the tube. Examples of such processes are shown in U.S. Pat. Nos. 2,876,496 and 3,509,252. Other processes entailed complicated apparatus which had to alternatively heat and cool a portion of the apparatus to form the closed end of the tube. Such a process is shown in U.S. Pat. No. 3,300,559. These complicated processes and apparatus were thought to be necessary to avoid excessive softening or melting and the resulting deformation of the plastic tubes. Other prior art processes for forming closed ends of tubes employed processes for beveling the edges of the tubes prior to the heating of the tubes to close the ends, such as that shown in U.S. Pat. No. 3,929,943.